Method for Mounting Blades on a Supporting Structure and Improved Fixing Element

ABSTRACT

The invention relates to an element for fixing ( 3 ) at least one modular coating blade ( 1 ) to a supporting structure ( 2 ), said element comprising: a base provided with a plane support face ( 6 ) to be fixed onto the supporting structure ( 2 ), and a fixing face ( 7 ) from which at least one protruding part ( 8 ) extends orthogonally, said protruding part to be engaged in a corresponding recess ( 4 ) in the blade ( 1 ). The projecting part ( 8 ) comprises tenons ( 10 ) on one free end ( 8   c ), said tenons progressively enlarging towards the fixing face ( 7 ) and facing an internal edge ( 19 ) of the recess ( 4 ), preventing the blade ( 1 ) from being removed. According to the invention, the protruding part ( 8 ) comprises a full tongue ( 8   a ) provided with means for rigidifying the same with the fixing face ( 7 ), the free end ( 8   c ) of said tongue being formed with the front ends of the tenons ( 10 ) joining at an acute angle, and the tenons ( 10 ) being separated from the full tongue ( 8   a ) adjacent to the rear ends thereof opposing those forming the acute angle.

The present invention relates to the general technical field ofattachment systems for planks or boards made of wood for example on asupport structure in order to create floors, floor coverings, or walls,and in particular outdoor decks.

The present invention relates to an attachment of wooden boards on asupport structure composed for example of wooden beams such as joistsand strips

The fastening of boards by screws is already known. Such fasteningassumes pre-drilling holes through the boards in a very precise patternin order to accurately define the positions of the screws. Screw socketsmust also be created to accommodate the screw heads. All the screws mustthen be tightened one after the other.

Such a fastening method requires the proper tools to be available atjobsites and takes a substantial amount of assembly time, particularlyfor the layout and screwing steps. Moreover, such a method producesboard flooring with visible screw heads, which mar the appearance ofsaid flooring.

Elements for fastening at least one modular covering board to a supportstructure are also known, comprising:

-   -   a base having a flat support face designed to be fastened to the        support structure of the joist or strip type,    -   a fastening face from which there extends orthogonally at least        one projecting part designed to engage in a corresponding recess        provided in the board and ending at a lower face of said board,    -   the projecting part having, at one free end, oblique tenons in        opposite directions and widening gradually in the direction of        the fastening face starting from the free end, whereby the        material of which the fastening element is made produces elastic        deformation of the projecting part when the board engages on        said projecting part,    -   the tenons are designed to be positioned opposite an internal        edge of the recess once the board is completely engaged on the        projecting part, which returns to its original shape when no        force is applied to it by the board, thus preventing the board        from retracting.

Document DE 20 2005 002 204 U1 describes for example a fastening elementdesigned to engage positively in a recess provided in a board. Theengagement is made possible because of the elastic deformationproperties of the fastening element, which has adequate flexibility. Thefastening element is made of synthetic material or aluminum. Since theuse of a fastening element has some flexibility, permitting engagementof the snap-in type, a mechanical link is often generated which could bealtered by stresses on the board. Also, the use of an aluminum fasteningelement is an expensive technical solution whose elastic deformationproperties are moreover not always satisfactory.

Outdoor decking is often subjected to substantial variations in heat andhumidity over the year, which can cause deformations in wood boards.Hence, these stresses must be taken into account to enhance the lifetimeof the deck. Exotic, very hard woods are often used for this purpose.

However, the boards may undergo contractions as large as 5 mm. Suchcontractions impose substantial stresses on the fastening systems andcontribute to weakening the link between the boards and the supportstructure.

Also, exposure of the upper faces of the boards to the sun causes unevendrying in the thickness of the boards. This phenomenon causesdeformation of the boards called “curling.” The “curling” phenomenoncauses the boards to assume a substantially concave or convex shape incross section. One or the other of these deformations generates stressesthat are substantially orthogonal to the support face of the boards, sothat the fastening elements are weakened or even broken. Thesedeformations can also cause the fastening elements to work their way outof their recesses in the board. With time, a less reliable join betweenthe support structure and the boards always occurs.

One goal of the present invention is to create a fastening element usedfor mounting boards in the form of a covering, of the outdoor deckingtype, enabling the boards to undergo size variations and deformationslinked to changes in temperature and humidity without altering thereliability of the mechanical join between the boards and the supportstructure.

Another goal of the present invention is to create a covering made ofwooden boards, for example an outdoor deck, with a fastening able toeffect simple and rapid mounting without resorting to specific mountingand assembly tools.

Another goal of the present invention is to optimize the performance ofsuch a fastening element while limiting its manufacturing cost.

According to the invention, the projecting part of the fastening elementhas a full tongue provided with stiffening means with the fasteningface, whose free end is formed with the front ends of the tenons meetingat an acute angle, the tenons being separated from the full tongue inthe vicinity of their rear ends opposite the ends forming the acuteangle, said rear ends being elastically deformable in order to comeclose to the full tongue when the board is engaged on the projectingpart.

Because of its optimized shape the fastening element has sufficientrigidity to prevent bending or twisting of its middle part comprised ofthe full tongue associated with the stiffening means.

The shape and dimensions of the tenons also enable the elasticdeformation properties in the engagement direction of a board, as wellas optimum rigidity in the reverse direction, to be conferred on thefastening element, thus preventing the board from pulling back.

The fastening element is made for example in a single piece by injectionor molding of a synthetic material.

According to one embodiment, the fastening face constituting the supportface of the board has longitudinally, on either side of each projectingpart, a substantially concave shape, obtained by adjusting the thicknessof the base. A fastening element is thus obtained whose board supportface has a shape that as exactly as possible matches the shapes of theboards that curl. When curling generates a substantially concave shape,it is the middle part of the board, viewed in cross section, and locatedbetween two projecting parts, that rests on the concave face of thefastening element. When curling brings about a substantially convexshape, viewed in cross section, it is the lateral ends of the boardlocated beyond two adjacent projecting parts, directed essentiallydownward, that match the beginning of a concave shape, being orientedsubstantially toward said fastening face.

In either case, the vertical forces acting on the fastening elements aresubstantially reduced, particularly on the projecting parts engaged inthe recesses of the board. This prevents premature wear of the fasteningand does not affect the irreversible engagement of the board with thefastening elements.

The fastening element according to the invention has, according to onepreferred embodiment, means for adjusting its lengthwise positioning onthe support structure, said adjusting means being stressable once thefastening element has been joined to the support structure.

The base of the fastening element has for this purpose local oblongareas with a smaller thickness, each designed to be traversed by afastening screw of said fastening element. The thickness is chosen suchas to allow displacement in the lengthwise direction of the fasteningelement under the effect of a lengthwise stress exerted on theprojecting parts. This displacement is made possible because of thecreep of material between the base and the fastening screw or screws.The oblong areas of smaller thickness are, for example, the bottoms ofbeveled cavities that are inserted between the conical heads of thefastening screws and the support structure. Contraction of the boardswill thus cause creep of the material of smaller thickness located atthe bottoms of the beveled cavities and traversed by the fasteningscrews so as to absorb said contraction by lengthwise displacement ofthe fastening element relative to the support structure. The fasteningelement according to the invention then has the advantage that a boardcan deform in various directions without generating harmful stresses onthe projecting parts.

Also, it is preferable to make the engagement of the boards on thefastening elements irreversible. For this purpose, it is desirable toincrease the stiffening of the projecting parts and allow them todeflect elastically for snapping engagement in the recesses of theboards. The elastic properties are then no longer useful in anirreversible mounting configuration. The greater the rigidity of theprojecting parts, the greater the irreversibility.

The use of means for stiffening the projecting parts thus improves theirreversibility of the mounting and reduces the risk that the boardswill pull back once mounted on their support structure. However, thequest for optimal rigidity increases the risk that the projecting partswill break if forces are generated in the lengthwise direction bylateral contraction of the boards. The possibility of absorbing such alateral contraction of the boards by sliding the fastening elements inthe lengthwise direction increases the service life of the fasteningelements on the one hand and remarkably improves the reliability of theirreversibility of the mounting of said boards on their supportstructure on the other hand.

According to one embodiment, the projecting part has a full tongue withharpoon-shaped tenons, said tenons being elastically deformable in alateral direction in order to move toward the full tongue when the boardengages. Engagement of the board on the fastening elements is thus doneby a snap-in type of operation.

According to one embodiment, the stiffening means are comprised of awidening of the lower part of the full tongue. The lower part alsoconstitutes the link between the base and the projecting part.

According to one embodiment, the stiffening means are comprised ofreinforcements, orthogonal relative to the fastening face, and integralwith the full tongue at the lengthwise or lateral ends of the latter.The sizes of the reinforcements are chosen to allow the projecting partto engage in the corresponding recess. Such stiffening means are veryeasy to make, particularly when produced in one piece with the fasteningelements, for example by plastic casting or injection. Thereinforcements can also serve as supporting elements for the boardengaged on the projecting part.

According to another embodiment of the invention, the projecting parthas two adjacent, parallel tabs, each having a tenon, so that the twotabs are urged together by elastic deformation when the tabs engage inthe recess. The adjacent tabs of a given pair are for example connectedwith each other in the vicinity of the base with at least one lengthwisestiffening edge.

According to one embodiment, each fastening element has severalprojecting parts and the base has, at its lengthwise ends, a dovetailshape for assembly with an adjacent fastening element. The dimensions ofthe fastening elements as well as the number of projecting parts on eachfastening element can be chosen according to the dimensions of theboards.

According to one embodiment, the fastening element has a millimetricscale, for example 1 to 592 mm.

The assembly according to the invention also allows a fixed gap betweentwo adjacent boards to be provided. This leads to good absorption of thedimensional variations in the wooden boards due to changes in humidityand temperature. Such a gap also enhances ventilation between the boardsand the joists, and the risk of water pooling leading to wood decay isthus greatly reduced.

Another non-negligible advantage is achieved by the fact that thenatural movements of the wood have no effect on the mechanicalconnection with the fastening elements. One useful feature emerges fromthe engagement or snapping in of the fastening elements in the recesses,thus producing a rigid, stable mechanical link without thereby placingstress on parts or areas of the wood experiencing this natural movement,or on the fastening elements.

The goals of the invention are also achieved with the aid of a mountingand assembling assembly of a covering including boards made of wood forexample to make a deck or floor and fastening elements such as thosereferred to above, the boards each having at least one recess in theshape of a lengthwise cavity whose shape matches that of the projectingparts of the fastening elements.

The mounting assembly also includes a support structure of the joist orstrip type supporting the boards, with the fastening elements effectinga mounting and fastening interface between the support structure and theboards.

Another advantage of the mounting assembly according to the inventionresides in the reduction of the wood's natural tendency to deform underthe action of the sun, by machining cavities and grooves on the lowerfaces of the boards. These cavities and grooves at least partly absorbthe natural strains inherent in wood that often cause twisting,cracking, and warping. The grooves constitute recesses provided in theboards.

Once assembled, the mounting assembly constitutes for example a deck, abalcony, a ceiling, or a vertical wall.

The goals of the invention are also achieved with the aid of a methodfor mounting modular covering boards on a support structure, consistingof:

-   -   using the aforesaid fastening elements,    -   positioning the boards such that the recesses face the        projecting parts,    -   and applying a pressure to an upper face of the boards in a        single direction orthogonal to the support structure to move and        engage the boards irreversibly on the projecting parts.

This gives the advantage of joining the boards to the support structureby a single snapping operation orthogonal to the supporting surface ofthe support structure. Moreover, this operation is irreversible because,once they are attached to the fastening elements, the boards can nolonger be removed by pulling them in a direction opposite to the snap-inengagement direction.

It is also possible to mount the fastening elements directly on thejoists in the shop and bring them to the jobsite equipped with thefastening elements. No particular tools are necessary for mounting theboards on the support structure. Thus they are quickly assembled,reducing material and labor costs.

For maintenance or replacement of deteriorating boards, the boards arecompletely disengaged by pulling on them in a lengthwise direction whichis the same as the lengthwise axis of the boards. This pulling causesthe cresses to slide on the corresponding fastening elements. Thus, thefastening elements are not damaged. Moreover, it is possible to removeone or more boards for repair work on a deck for example and them snapthem back in without damaging either the boards or the fasteningelements.

Because of the invention, attachment means that are invisible at theupper faces of the covering boards are obtained.

The mounting method according to the invention also enables boards ofsignificant length to be used, for example between 2 and 3 meters,particular with the use of Brazilian Ipe boards known for their decayresistance and superior quality, also for their straightness.

Other features and advantages will also emerge from the detaileddescription provided below with reference to the attached drawings ofnon-limitative examples, wherein:

FIG. 1 is a schematic cross-sectional representation showing, onceassembled, a board, a support structure, and an embodiment of afastening element according to the invention,

FIG. 2 is a top view of an embodiment of a fastening element accordingto the invention;

FIG. 3 is a profile view of the fastening element in FIG. 2;

FIG. 4 is a detailed, perspective view of the fastening element in FIGS.2 and 3;

FIG. 5 shows schematically an assembly of boards on a support structurethanks to a fastening element according to the invention;

FIG. 6 is a partial perspective view of a second embodiment of thefastening element according to the invention;

FIG. 7 is a partial perspective view of a third embodiment of thefastening element according to the invention;

FIG. 8 shows an assembly of boards on a support structure with thefastening element shown in FIG. 7.

FIG. 9 is a partial perspective view of an embodiment of the fasteningelement according to the invention, having a means for adjusting itsposition relative to the support structure;

FIG. 10 shows an assembly example of two fastening elements according tothe invention of FIG. 9;

FIG. 11 is a partially enlarged, perspective view of the fasteningelement of FIG. 9;

FIG. 12 shows schematically an example of assembly and lengthwisepositioning of boards on fastening elements according to the invention;

FIGS. 13 to 15 show schematically the stresses and strains experiencedby the boards mounted on a support structure by means of the fasteningelements according to the invention;

FIG. 16 shows completely and in perspective the fastening element ofFIGS. 9 and 11;

FIGS. 17 and 18 show a top view and profile view respectively of thefastening element of FIG. 16;

FIG. 19 is an enlarged detail of FIG. 18;

and FIG. 20 shows schematically an example of the deformation of afastening element according to the invention undergoing stresses.

FIG. 1 shows an example of mounting a covering board (1) on a supportstructure (2). The latter is for example an arrangements of joists orstrips at regular intervals. The board (1) is attached to the supportstructure (2) by fastening elements (3). Each board (1) has two recesses(4) opening into an inside face (5) designed to face the supportstructure (2).

The fastening element (3) according to the invention and shown in FIGS.2, 3, and 4 has an essentially flat base with a lower face (6) designedto rest on the support structure (2) and an upper face (7) from which atleast one projecting part (8) in the form of locking tabs (9) extendsessentially orthogonally. The lower face (6) thus rests on an uppercontact face (2 a) of the support structure (2).

The locking tabs (9) have tenons (10) that are oriented obliquely awayfrom the locking tab (9) in the direction of the base. The tenons (10)of two adjacent locking tabs (9) extend in opposite directions andobliquely toward the base, in the lengthwise direction of the fasteningelement (3). The tenons (10) are advantageously shaped to prevent anyboard (1) from pulling back once the locking tabs (9) are completelyengaged in the corresponding recess (4) of board (1).

According to one embodiment, each fastening element (3) has severalpairs of locking tabs (9) distributed along its lengthwise extension.Each fastening element (3) has for example six or eight pairs of lockingtabs (9).

It is also possible to provide, on each fastening element (3), amillimetric scale, for example from 1 to 592 mm, facilitating thecutting of this fastening element (3) according to the desired length.

The base of the fastening element (3) also has holes (11) for passage offastening screws (12) between the locking tabs (9) of a given pair. Thisenables the fastening elements (3) to be screwed to the supportstructure (2).

A shape of the dovetail type (13, 14) can be provided at the lengthwiseends of each fastening element (3) for assembly with the adjacentfastening element (3). The ends (13, 14) are for example beveled tofacilitate their interlocking. This provides control over the regularityof the gaps between the projecting parts (8) of two sequential fasteningelements (3). It is thus possible to fully control the regularity of thegaps (15) between the boards (1). This gap (15) is for example between 3and 5 mm. The gap (15) not only enables water spilling onto the upperfaces (5 a) of the boards (1) to be drained but also the dimensionalvariations in said boards to be at least partly absorbed.

Full control of the regularity of the gaps (15) also improves the visualappearance of the covering effected by a succession of boards (1).

The projecting parts (8) also have stiffening means. The locking tabs(9) of a given pair are thus connected to each other in the vicinity ofthe base with a stiffener (16) that constitutes a stiffening means. Thestiffening edge (16) confers on the locking tabs (9) increasedresistance to deforming stresses in the recess (4) that in general acton the projecting parts (8). The stiffened locking tabs (9) are lesssubject to deformation, rendering the fastening of the board (1) morereliable by ensuring irreversibility of the mounting of the boards (1)on the support structure (2). This increased stiffness also affordsbetter resistance to any momentary strains on the wood caused by changesin humidity and/or temperature.

The tenons (10) have sloping front faces (17) that engage in the recess(4) to urge together the sloping front faces (17) of the locking tabs(9) by elastic deformation.

Each tenon (10) also has a holding face (18) essentially parallel to theupper face (7) that comes into position opposite an inside edge (19) ofrecess (4) once board (1) is completely engaged and the locking tabs (9)have returned to their initial resting positions. For this purpose, therecess (4) has the shape of a lengthwise cavity ending at the insideface (5) of board (1), whose side walls each have a groove (20) in orderto present an essentially T-shaped cross section. Reference may be madefor example to FIG. 1. This groove (20) is hence delimited partially bya bottom (4 a) of the recess and laterally, opposite and facing saidbottom (4 a), by the inside edge (19). When board (1) is completelyengaged on the fastening element (3), the holding faces (18) constitutestops for the inside edges (19), preventing the board (1) from pullingback in the direction opposite to its engagement direction.

The inside edges (19) cannot be released from the stop constituted bythe corresponding holding faces (18), thus providing an irreversibleassembly of the boards (1).

One example of the assembly of boards (1) on a support structure (2) bymeans of the fastening elements (3) according to the invention is shownfor example in FIG. 5. The boards (1) are engaged in a single direction.

Three variants of the fastening elements (3) according to the inventionare shown in FIGS. 6, 7, and 9. The projecting part (8) in theseembodiments has a full tongue (8 a) with harpoon-shaped tenons (10). Thetenons (10) are elastically deformable in a lateral direction so thatthey come close to the full tongue (8 a) when board (1) is engaged onthe fastening elements (3).

In the embodiment shown in FIGS. 7 and 8, the stiffening means of theprojecting part (8) are constituted by a widened part (8 b) of the lowerpart of the full tongue (8 a). The projecting part (8) thus has a freeend (8 c), whereby the tenons (10) form an acute angle and becomeprogressively larger in the direction from said free end (8 c) downward.An appropriate choice of the material of which the fastening element(3), including projecting parts (8), is made then ensures lateralelastic leveling off of the tenons (10) when board (1) is engaged onprojecting part (8). The tenons (10) must however have sufficientstrength for them to resist when a pullback force is applied to boards(1) in the direction opposite their engagement direction on thefastening elements (3). For this purpose, tenons (10) are detached fromthe full tongue (8 a) only in the vicinity of their rear ends, oppositetheir forward ends forming an acute angle.

FIG. 8 shows in cross section a board (1) mounted on a support structure(2) by a fastening element (3) according to the invention. The fasteningelement (3) is attached to the support structure (2) by screws (12). Therecesses (4) are in the form of lengthwise cavities whose essentiallyV-shape in cross section matches that of the projecting parts (8) of thefastening elements (3). The recesses (4) then perfectly match theharpoon shape of the projecting parts (8) when the board (1) is fullyengaged on the fastening element (3). The recesses (4) also have insideedges (19) that abut the holding faces (18) of the tenons (10) as soonas the board (1) is completely engaged on the fastening elements (3).

FIG. 9 shows another embodiment of a fastening element (3) according tothe invention, having means for adjusting its lengthwise position on thesupport structure once it is attached to said support structure (2).

The adjusting means comprise areas of lesser local thickness (22),oblong in shape and designed to be traversed each by a fastening screw(12). The locally less-thick areas (22) each corresponding for exampleto a bottom of an oblong beveled recess (23), provided in the fasteningface (7) of the fastening element (3). This lesser thickness is chosenso as to allow slight movement in the lengthwise direction of thefastening element (3) under the effect of a lengthwise stress applied tothe projecting parts (8). This movement is made possible because of thecreep property of the material of which the locally less-thick areas(22) are made between the base and the fastening screw (12). Thefastening elements (3) can then move relative to the fastening screws(12) passing through them.

In this way it is possible to absorb the stresses generated bycontraction of the boards (1) for example in direction C1 or directionC2 shown in FIGS. 13, 16, and 20. When a board (1) generatessimultaneous stresses in directions C1 and C2 opposite the adjacentprojecting parts (8) on which it is engaged, lengthwise displacement,specifically coming together, is achieved between these two projectingparts (8) because of the creep property of the material of which thelocally less-thick area (22) is made. Reference may be made inparticular to FIGS. 16 and 20. The stresses in directions C1 and C2corresponding to contraction of the board (1) thus cause deformation ofthe base in a direction F shown schematically in FIG. 20. Thisdeformation F is located between two adjacent projecting parts (8)engaged in the same board (1).

Between two adjacent projecting parts (8) each engaged in a separateboard that contracts, a slight extension is observed of the baseconnecting said projecting parts (8). The fastening element (3)according to the invention thus has a base of which a first portion (3a) undergoes a deformation and of which a second portion (3 b) undergoesan extension when the boards (1) contract. Reference may be made forexample to FIG. 16.

In the example of FIG. 6, the stiffening means of the projecting part(8) are comprised of reinforcements (24) extending orthogonally relativeto the fastening face (7). These reinforcements (24) are integral withthe full tongue (8 a) at the lengthwise ends of the latter. Thereinforcements (24) have smaller overall dimensions than those of theprojecting part (8) in order not to interfere with the engagement ofsaid projecting part (8) in the corresponding recess (4). Thereinforcements (24) are for example made in a single piece with thefastening element (3).

In the embodiment shown in FIG. 9, reinforcements (24) extendorthogonally relative to the base in the rising direction along the fulltongue (8 a) The reinforcements (24), of the rib type, are located onthe one hand on each side of the full tongue (8 a) and on the other handbetween the pairs of tenons (10) of each projecting part (8). Thisprovides optimal stiffening of the projecting part (8).

The second portion (3 b) of the base also has breaks (3 c). These enablethe fastening element (3) to be broken off more easily, without tools,to adjust its length to the number of boards (1) used for a floorcovering or a deck.

The fastening face (7) constituting the support face of the board (1)has longitudinally, on either side of each projecting part (8), asubstantially concave shape (7 a) obtained by gradual, continuousadjustment of the thickness of the base of the fastening element (3).Reference may be made for example to FIGS. 13 to 19. Thus it is thefirst and second portions of the base (3 a, 3 b) that have thesubstantially concave shape (7 a).

When board (1) is not deformed (see FIG. 13), it rests on the fasteningelement (3) in the vicinity of the projecting parts (8). On the otherhand, when board (1) curls, meaning a deformation indicated by arrows D1and D2 in FIGS. 14 and 15, the inside face (5) of board (1) deforms inthe concave shape (7 a) of the fastening face (7). When curling occursin the direction indicated in FIG. 14, it is the middle part of theboard (1) located between projecting parts (8) that rests on the concavepart (7 a). The lateral ends of board (1) are oriented slightly upward,going away from the fastening face (7). Since board (1) can deform,matching the concave shape (7 a) located between projecting parts (8),there is a significant reduction in vertical stresses acting on theprojecting parts (8). In the absence of a concave shape (7 a) onfastening face (7), the deformation shown schematically in FIG. 14 wouldresult in the projecting parts (8) being pulled essentially in thedeformation direction D1.

Furthermore, when a deformation occurs as indicated in FIG. 15, it isthe lateral ends of board (1) that deform in the concave shapes (7 a)located beyond each of the two adjacent projecting parts (8) and engagedin the same board (1). Since absorption of this deformation by thefastening element (3) is accompanied by lifting of the middle part ofthe board (1), the vertical forces applied to the projecting parts (8)in essentially direction D2 are considerably reduced. In the absence ofsuch a concave shape (7 a) facing the lateral ends of board (1),deformation of the middle part of board (1) would lead to the projectingparts (8) being pulled in a direction D2, encouraging the attachment tobreak off.

The fastening element (3) according to the invention thus substantiallyreduces the stresses linked to a curling phenomenon that would damagethe integrity of the fastening over time.

Advantageously, the base of the fastening elements (3) has gaps (21)that in particular afford material savings in manufacture. The fasteningelements (3) are made for example in a single piece by injection orcasting of a synthetic material of the polypropylene, POM, or PA type.

The method according to the invention of assembling modular coveringboards (1) on the support structure (2) thus consists of using thefastening elements (3) to attach the boards (1) to the support structure(2) and integrate said fastening elements (3) with said supportstructure (2).

According to another step in the method according to the invention, itis appropriate to position the boards (1) with their recess (4) facingthe projecting parts (8) of the fastening elements (3).

Next, according to an additional step, it is appropriate to move theboards (1) in a single direction (E) (see FIG. 5) that is substantiallyorthogonal to the extension plane of the support structure (2)corresponding for example to the upper contact faces (2 a) of joists toirreversibly engage the fastening elements (3) in the recess or recesses(4) by a snap-in type of operation. This operation consists of applyingpressure to the upper faces (5 a) of boards (1).

Assembly of boards (1) is thus achieved extremely simply with a minimumof assembly operations, with preparation being limited to machining therecesses (4) in each of the boards (1).

According to one implementation example of the method according to theinvention, it is possible to adjust the positions of the boards (1) bysliding them in the lengthwise direction (A) of the recess or recesses(4) as shown for example in FIG. 12.

The present invention also relates to an apparatus for mounting andassembling a covering from which, after assembly, a deck, balcony,floor, vertical wall, or ceiling can be made. It is thus particularlyuseful to employ the fastening elements (3) according to the inventionfor weather-boarding or siding operations.

Without departing from the framework of the present invention, theboards (1) can be made of a synthetic material of the composite woodtype.

It is also possible, without departing from the framework of the presentinvention, to transpose the technical features of one embodiment of thefastening element (3) to another embodiment of said fastening element(3). Thus it is possible to provide on the fastening element (3) shownfor example in FIG. 1 a concave shape (7 a) of the fastening face (7)between the locking tabs (9) of two adjacent projecting parts (8). Inaddition, means for adjusting the lengthwise position of the fasteningelement (3) on the support structure (2) can also be provided in theembodiment shown in FIG. 1 or 7.

1. Element for fastening at least one modular covering board on asupport structure having a base with a flat support face designed to beattached to the support structure of the joist or strip type, afastening face from which extends orthogonally at least one projectingpart designed to engage in a corresponding recess provided in the boardthat ends at the lower face of said board, the projecting part having atone free end tenons oriented in oblique directions and wideninggradually in the direction of the fastening face starting from the freeend, whereby the material of which the fastening element is made ensureselastic deformation of the projecting part when board engages saidprojecting part (8), tenons designed to be positioned facing an insideedge of the recess once the board is completely engaged on theprojecting part, which resumes its original shape when not beingstressed by board, thus preventing the board from pulling back, whereinthe projecting part has a full tongue provided with stiffening meanswith the fastening face, the free end of which is formed with the frontends of the tenons meeting at an acute angle, the tenons being separatedfrom the full tongue in the vicinity of their rear ends opposite thoseforming the acute angle, said rear ends being elastically deformable ina favored direction because of their slope, in order to move closer tothe full tongue when the board is engaged on the projecting part. 2.Fastening element according to claim 1, wherein the fastening faceconstituting the support face of board has longitudinally, on eitherside of each projecting part, a substantially concave shape, obtained byadjusting the thickness of the base.
 3. Fastening element according toclaim 1, wherein having means for adjusting its longitudinal position onthe support structure, said adjusting means being stressable andactivatable once the fastening element has been attached to the supportstructure.
 4. Fastening element according to claim 3, wherein theadjustment means have local areas of smaller thickness that are oblongat the base, and are designed each to be traversed by a fastening screwof said fastening element, said thickness being chosen such as to allowdisplacement in the lengthwise direction of the fastening element underthe effect of a lengthwise stress exerted on the projecting partsbecause of the material creep between the base and the fastening screwor screws.
 5. Fastening element according to claim 1, comprising thestiffening means being comprised of a widening of the lower part of thefull tongue.
 6. Fastening element according to claim 1, wherein thestiffening means are comprised of reinforcements that are orthogonal tothe fastening face and integral with the full tongue at the longitudinalor lateral ends of the latter, the dimensions of the reinforcementsbeing chosen to enable the projecting part to engage in thecorresponding recess.
 7. Fastening element according to claim 1, whereinhaving several projecting parts.
 8. Fastening element according to claim1, wherein the base has, at its lengthwise ends, a dovetail shape forassembly with an adjacent fastening element.
 9. Fastening elementaccording to claim 1, wherein having a millimetric scale, for examplefrom 1 to 592 mm.
 10. Fastening element according to claim 1, whereinthe fastening element is made in a single piece by injection or moldingof a synthetic material.
 11. Apparatus for mounting and assembling acovering comprising boards made of wood for example, for making a deckor floor, and fastening elements according to claim 1, the boards eachhaving at least one recess in the shape of a lengthwise cavity, theshape of which at least partly matches that of the projecting parts ofthe fastening elements.
 12. Apparatus according to claim 11, wherein,the apparatus forms, once assembled, a deck, a balcony, a floor, avertical wall, or a ceiling.
 13. Method for mounting modular coveringboards on a support structure, comprising: using fastening elementsaccording to claim 1, positioning the boards such that the recesses facethe projecting parts, and applying a pressure to an upper face of theboards in a single direction orthogonal to the support structure to moveand engage the boards irreversibly on the projecting parts.
 14. Mountingmethod according to claim 13, further comprising adjusting thepositioning of the boards by sliding in the lengthwise direction of therecesses.